Ventilation system with axial fan and integrated accelerator/deflector

ABSTRACT

A ventilation system for an air or gaseous fluid has a housing having an inlet ( 50 ) and an outlet ( 52 ), an axial fan ( 16 ) and an accelerating/deflecting structure ( 18 ). The axial fan has a casing ( 36 ) attached to the housing. Moreover, the axial fan ( 16 ) has a motor mounted within the casing and blades ( 32 ) also mounted within the casing to generate a flow of said fluid in an axial direction. The accelerating/deflecting structure ( 18 ) is devised and positioned to orient the flow generated by the axial fan ( 16 ) in a direction transverse to said axial direction. The accelerating/deflecting structure ( 18 ) can either be mounted upstream or downstream of the axial fan ( 16 ). Furthermore, the accelerating/deflecting structure ( 18 ) can either be mounted within or outside the housing.

RELATED APPLICATION(S)

This application is a continuation of International Patent ApplicationNo. PCT/CA2004/000179 filed on Feb. 10, 2004, which claims benefit ofCanadian Patent Application Nos. 2,418,636 and 2,447,334 filed on Feb.10, 2003 and Oct. 31, 2003 respectively, which are herein incorporatedby reference.

FIELD OF THE INVENTION

The present invention generally relates to fans used in a residential,commercial, industrial and institutional context. More precisely, theinvention relates to a new ventilation system with an axial fan and,preferably, an integrated accelerator/deflector.

BACKGROUND OF THE INVENTION

In standard ventilation systems, in particular those used in bathrooms,the fan motor is always fixed to a support, either on an innerventilator wall opposite the air inlet or on a wall adjacent to theinlet. Such a configuration causes turbulence problems in the fluid flowto be evacuated as well as creating phenomena of air backflow and noise.Another problem associated with standard ventilation systems arises fromthe transmission of vibrations from the motor to its support structure,with the noise generated by this transmission.

French patent FR 1255721 teaches a ventilator suspension system,particularly for kitchen ventilators, for which reductions in noiseduring its operation is a very important feature. This inventiondescribes a suspension system that allows significant tangential motionof the axial fan motor which is suspended in a surrounding structure,while reducing axial motion of the fan motor, thus significantlyreducing the noise being output from the ventilator.

German patent DE 91 08 745 U1 discloses a motor support systemcomprising a holding body made of rubber-elastic material with asurrounding ring part which spans around an intermediate bushsurrounding a stator of an electric motor and holds in on a motorholder. In this construction, three arm parts are additionally providedwhich are uniformly distributed along the circumference, are molded ontothe ring part and cause an additional support between the motor housingand the intermediate bush.

Most ventilators used in washrooms rely on propeller or centrifugal fansto create the required airflow through the ventilator.

Unfortunately, prior art devices in this field frequently are prone topremature clogging and corrosion, while having disappointingperformances in terms of ventilating capacity.

In spite of the teachings of prior art, the above-described problems andissues with standard ventilation systems remain. Thus there still existsa need for a ventilation system which can better avoid the existingproblems of turbulence, backflow, noise and vibration as well as theproblems of premature clogging and corrosion.

SUMMARY OF THE INVENTION

It is an object of the invention to provide a new ventilation systemwith an axial fan and, preferably, an integrated accelerator/deflector.

Even though the system described hereinafter and shown in the followingdrawings is essentially an air ventilation system designed forwashrooms, it can also be used in other fields including audio-videosystems, home appliances, ventilation systems, heating/refrigeration,kitchens, air conditioning, as well as ventilation systems made toforcibly evacuate smoke, heat or different gases or residues.

A first original feature of the present invention resides principally inthe positioning and use of an axial fan which is fixed to the housing ofthe ventilator being used to evacuate the air (or other gaseous fluid).Another original feature of this invention resides in that the air orgaseous fluid must flow through an accelerator/deflector integrated tothe ventilator housing and either mounted within or outside the housing,in order to improve the flow towards the ventilator outlet.

More specifically, the invention provides a ventilation system for anair or gaseous fluid comprising a housing having an inlet and an outlet,an axial fan and an accelerating/deflecting structure. The axial fancomprises a casing attached to the housing. The axial fan furthercomprises a motor mounted within the casing and blades also mountedwithin the casing to generate a flow of said fluid in an axialdirection. The accelerating/deflecting structure is devised andpositioned to reorient the flow generated by the axial fan in adirection transverse to said axial direction. Theaccelerating/deflecting structure can either be mounted upstream ordownstream of the axial fan. Furthermore, the accelerating/deflectingstructure can either be mounted within or outside the housing.

The present invention eliminates the backflow and air leak problemsthrough a positioning of the axial fan which is assembled between twowalls of the ventilator housing and using a sealing element between thefan and the housing. This type of assembly, when used in combinationwith an accelerator/deflector integrated to the housing, improves thefluid flow through the ventilator and therefore results in improvedperformance with respect to the ventilating capacity of the system. Theaccelerator/deflector improves the efficiency in terms of flow(inft³/min) at the outlet of the ventilator, as it decreases turbulencein the flow.

The ventilation system according to the present invention offersperformances several times superior to those obtained with prior artsystems used in the above-mentioned fields for the removal of air fromenclosed spaces. Furthermore, this system facilitates removal ofundesirable particulate matter including mould, bacteria, solventvapours, toxic gases, pesticides, foul odours, carbon monoxide, cookingresidues, and dust. Moreover, when used, for example, in combinationwith Ventiflex™-type ducting which is known as a flexible, lightweight,durable ducting specifically designed to optimise the conveying of largevolumes of air, safely and cleanly, performance is exceptional. Thesystem has been designed to operate in different environments of varyingtemperature and humidity.

The system according to the present invention not only results inimproved performance with respect to overall air flow, but also resultsin remarkable acoustic qualities surpassing those of existingventilation systems under similar conditions. In addition, as opposed tosystems that currently exist in the market, the noise level of theventilator of the present invention does not increase proportionallywith an increase in the airflow going through it.

In addition to the above-mentioned advantages, the ventilation systemaccording to the invention does not require any maintenance or cleaningduring all of its useful life, while existing systems tend to get dirtywith dust and residues floating in the air. Moreover, the system is notvulnerable to corrosion in normal operating conditions in the presenceof humid air in a washroom or any chemical fume produced by anindustrial process, contrary to existing ventilation systems.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention and its advantages will be more easily understoodafter reading the following non-restrictive description of preferredembodiments thereof, made with reference to the following drawings inwhich:

FIG. 1 is a perspective view of a ventilation system according to afirst preferred embodiment of the invention wherein anaccelerator/deflector is mounted outside the ventilator housing;

FIG. 2 shows a cut perspective view of a ventilation system according toa second preferred embodiment of the invention wherein anaccelerator/deflector is mounted within the ventilation system housing;

FIG. 3 shows a cut perspective view of a ventilation system according toa third preferred embodiment of the invention wherein anaccelerator/deflector similar to the one shown in FIG. 1 is mountedwithin the ventilation system housing;

FIG. 4 is an exploded view of the axial fan used in the ventilationsystem shown in the previous figures;

FIG. 5 is a cut side view of the ventilation system shown in FIG. 1; and

FIG. 6 is a cut side view of the ventilation system shown in FIG. 2.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

In the first preferred embodiment of the invention shown in FIGS. 1 and5, the ventilation system (10) for air or other gaseous fluids comprisesa housing (12) through which the air or fluid flows. An axial fan (16)is fixed to the housing (12). The ventilation system (10) also comprisesan accelerator/deflector (18) used to improve the air or fluid flowthrough the housing (12).

FIG. 2 shows another type of ventilation system (10) according to asecond preferred embodiment of the invention, wherein theaccelerator/deflector (18) is mounted within the ventilation systemhousing (12).

FIG. 3 shows a cut perspective view of a ventilation system (10)according to a third preferred embodiment of the invention, wherein anaccelerator/deflector (18) similar to the one shown in FIG. 1 is mountedwithin the ventilation system housing (12).

As shown in FIG. 4, the axial fan (16) comprises a motor (20) in whichtwo sets of ball bearings (24 and 26) are installed on either end of thedrive shaft (22) which transmits the motor power. This type of motorassembly creates a better dynamic equilibrium when the motor is running.Moreover, this type of motor assembly decreases significantly problemsrelated to bending moments in standard motor assemblies that have rotorblades placed at one of the extremities of the drive shaft. Thisaccentuates problems due to the forces which sometime overcome theelastic limits of the materials used in such motor assemblies and thuslead to irreparable plastic deformations which are responsible for thepremature wear of different components, including the ball bearings, therotor blades and even the drive shaft.

Also as shown in FIG. 4, the motor (20) comprises a stator (28) and arotor (30). Blades (32) for the fan are attached directly to the rotor(30) and are built as a single unit. When assembled with the stator(28), this type of assembly results in improved dynamic stability asradial and axial forces are reduced and the useful lifetime ofcomponents is increased compared to existing products. In addition, aspring element (34) is placed between the two sets of ball bearings (24and 26) which creates a constant tensile axial force and results inimproved stability. The ball bearings (24 and 26) are tightly installedto create a proper radial balancing effect and therefore a betterdynamic equilibrium effect for rotational speeds varying between 400 and10 000 rpm.

A motor casing (36) covers all the motor (16) components. The motorcasing (36) comprises support arms (38) which link the center of thecasing (35) holding the motor (16) assembly to the external part (40) ofthe casing (36). A sealing element (42) is installed around theperiphery (44) of the casing (36). With the motor casing (36) installedin the ventilator housing (12), the sealing element (42) is theprincipal contact element between the fan (16) and the external wall(14) of the housing (12). This type of assembly eliminates air leaksfrom the housing (12) as well as decreases the transmission ofvibrations from the moving parts of the motor (16) to the housing (12).

FIGS. 5 and 6 are cut side views of the ventilation systems shown inFIGS. 1 and 2 respectively. These figures illustrate the common aspectsbetween the two systems according to preferred embodiments of thepresent invention. In both cases, the ventilation system (10) comprisesa housing (12) having an inlet (50) and an outlet (52), an axial fan(16) and an accelerating/deflecting structure (18). The axial fan (16)comprises a casing (36) attached to the housing (12). The axial fan (16)further comprises a motor (20) mounted within the casing (36) and blades(32) also mounted within the casing (36) to generate a flow of saidfluid in an axial direction. The accelerating/deflecting structure (18)in both cases is devised and positioned to orient the flow generated bythe axial fan (16) in a direction transverse to said axial direction.

In an alternate preferred embodiment, the locations of the axial fan andthe accelerator/deflector are reversed with respect to each other. Inthis configuration, the accelerating/deflecting structure is mountedupstream of the axial fan, instead of downstream as described in theprevious embodiments.

The system in accordance with a preferred embodiment of this inventionshown in the drawings is generally made of metallic materials. However,the invention is not limited to that type of material. The system canthus be manufactured from different plastics, composite materials orvarious alloys. Furthermore, the shape of the axial fan motor, the motorcasing, the shape of the accelerator/deflector, the shape of the housingand the rotor blade shapes are elements among others that could bemodified without departing from the scope of the present invention.

A system as shown has been manufactured from the following materials andhas proved to offer the following performance characteristics: ElementsCharacteristics Outer housing Aluminum Blade material Plastic reinforcedwith thermoplastic glass PBT.UL94V-0 Operating temperature −20° C. to80° C. Power requirements 1 min to 1500 VAC 50/60 Hz 110 V/60 Hz and 220V/50 Hz Standards E176286, CSA: LR109863-1, P/N 1123HBT Air flow Varyingbetween 10 and 15 000 ft³/min Rotational speed of fan Varying between400 and 10 000 rpm Electrical Current Varying between 0.10 and 20 AStatic pressure 5.8 to 7 mm of water

Although the present invention has been explained hereinabove by way ofa preferred embodiment thereof, it should be pointed out that anymodifications to this preferred embodiment within the scope of theappended claims s not deemed to alter or change the nature and scope ofthe present invention. The great rigidity, stability, durability, highcapacity and low noise output qualities of this new system makes it aninteresting product for use in several fields as described above.

1. A ventilation system for an air or gaseous fluid comprising: ahousing having an inlet and an outlet; an axial fan; and anaccelerating/deflecting structure, wherein the axial fan comprises acasing attached to the housing, a motor mounted within the casing andblades also mounted within the casing to generate a flow of said fluidin an axial direction, and wherein the accelerating/deflecting structureis devised and positioned to orient the flow generated by the axial fanin a direction transverse to said axial direction.
 2. A ventilationsystem according to claim 1 wherein the accelerating/deflectingstructure is mounted downstream of the axial fan.
 3. A ventilationsystem according to claim 1 wherein the accelerating/deflectingstructure is mounted upstream of the axial fan.
 4. A ventilation systemaccording to any one of claims 1 to 3 wherein theaccelerating/deflecting structure is mounted within the housing.
 5. Aventilation system according to any one of claims 1 to 3 wherein theaccelerating/deflecting structure is mounted outside the housing.
 6. Theventilation system according to any one of claims 1 to 5 wherein theaxial fan motor further comprises a stator and a rotor and wherein theblades are integrated to the rotor to form a single component.
 7. Theventilation system according to any one of claims 1 to 6 wherein theaxial fan motor comprises a drive shaft surrounded by a spring elementand a set of ball bearings located at both ends of the spring element.8. The ventilation system according to any one of claims 1 to 7 whereina sealing medium is located at the interface where the housing and theaxial fan casing are attached to each other.
 9. Use of the ventilationsystem according to any one of claims 1 to 8 for ventilation of awashroom.
 10. Use of the ventilation system according to any one ofclaims 1 to 8 for ventilation of audio-video systems and homeappliances.
 11. Use of the ventilation system according to any one ofclaims 1 to 8 for ventilation in air conditioning systems.
 12. Use ofthe ventilation system according to any one of claims 1 to 8 forevacuation of smoke, heat, gases and residues from rooms.